linux-kernel - [tip: objtool/urgent] objtool/klp: Fix unexported static call key access for manually built livepatch modules

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Message-ID: <177030803819.2495410.14095810882510508232.tip-bot2@tip-bot2>
Date: Thu, 05 Feb 2026 16:13:58 -0000
From: "tip-bot2 for Josh Poimboeuf" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Arnd Bergmann <arnd@...db.de>, Song Liu <song@...nel.org>,
 Josh Poimboeuf <jpoimboe@...nel.org>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: objtool/urgent] objtool/klp: Fix unexported static call key
 access for manually built livepatch modules

The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID:     f495054bd12e2abe5068e243bdf344b704c303c6
Gitweb:        https://git.kernel.org/tip/f495054bd12e2abe5068e243bdf344b704c303c6
Author:        Josh Poimboeuf <jpoimboe@...nel.org>
AuthorDate:    Mon, 02 Feb 2026 11:00:17 -08:00
Committer:     Josh Poimboeuf <jpoimboe@...nel.org>
CommitterDate: Thu, 05 Feb 2026 08:00:45 -08:00

objtool/klp: Fix unexported static call key access for manually built livepatch modules

Enabling CONFIG_MEM_ALLOC_PROFILING_DEBUG with CONFIG_SAMPLE_LIVEPATCH
results in the following error:

  samples/livepatch/livepatch-shadow-fix1.o: error: objtool: static_call: can't find static_call_key symbol: __SCK__WARN_trap

This is caused an extra file->klp sanity check which was added by commit
164c9201e1da ("objtool: Add base objtool support for livepatch
modules").  That check was intended to ensure that livepatch modules
built with klp-build always have full access to their static call keys.

However, it failed to account for the fact that manually built livepatch
modules (i.e., not built with klp-build) might need access to unexported
static call keys, for which read-only access is typically allowed for
modules.

While the livepatch-shadow-fix1 module doesn't explicitly use any static
calls, it does have a memory allocation, which can cause
CONFIG_MEM_ALLOC_PROFILING_DEBUG to insert a WARN() call.  And WARN() is
now an unexported static call as of commit 860238af7a33 ("x86_64/bug:
Inline the UD1").

Fix it by removing the overzealous file->klp check, restoring the
original behavior for manually built livepatch modules.

Fixes: 164c9201e1da ("objtool: Add base objtool support for livepatch modules")
Reported-by: Arnd Bergmann <arnd@...db.de>
Acked-by: Song Liu <song@...nel.org>
Tested-by: Arnd Bergmann <arnd@...db.de>
Link: https://patch.msgid.link/0bd3ae9a53c3d743417fe842b740a7720e2bcd1c.1770058775.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
---
 tools/objtool/check.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 933868e..ef451cd 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -682,7 +682,7 @@ static int create_static_call_sections(struct objtool_file *file)

 		key_sym = find_symbol_by_name(file->elf, tmp);
 		if (!key_sym) {
-			if (!opts.module || file->klp) {
+			if (!opts.module) {
 				ERROR("static_call: can't find static_call_key symbol: %s", tmp);
 				return -1;
 			}